Guides / E1390
E1390 Oxygen concentrator, stationaryMedicare Home Oxygen Documentation Requirements (E1390)
Citations verified against the CMS Medicare Coverage Database · Reviewed September 2026
Home oxygen has the most numeric coverage criteria in DME: qualification hinges on actual blood gas values — an arterial pO2 at or below 55 mmHg, or oxygen saturation at or below 88% at rest on room air (Group I) — measured while the patient is in a chronic stable state, not during an acute illness. Borderline values (pO2 56–59 / SpO2 89) can still qualify under Group II with specified secondary findings.
These are the checks AffirmDME runs on every E1390 case — including reading the actual SpO2/pO2 numbers out of the testing report and evaluating them against the thresholds, with borderline values flagged for clinical review rather than auto-failed.
The requirements, with citations
Every item below is a check AffirmDME runs automatically — this list mirrors the production rules engine, not a paraphrase of the regulations.
Qualifying blood gas values
Arterial pO2 at or below 55 mmHg, or SpO2 at or below 88%, taken at rest on room air. The actual report — with the numbers — must be in the record; AffirmDME evaluates the extracted values against the thresholds and flags borderline Group II results for review.
LCD L33797 — Group I qualifying valuesTesting in a chronic stable state
The qualifying test must not be taken during an acute illness or an exacerbation — the record should affirmatively describe a stable outpatient state with medical management optimized.
LCD L33797 — chronic stable stateRecent qualifying test
The qualifying study must be recent relative to the initial claim (AffirmDME applies a conservative ~30-day window). A months-old oximetry reading doesn't establish current need.
LCD L33797 — qualifying test recencyHypoxemia condition and treatment documented
Clinical notes must document the underlying condition causing hypoxemia and that alternative treatment has been considered or optimized.
Policy Article A52514 — oxygen documentationStandard Written Order (SWO) on file
A complete written order must exist before the claim is submitted — patient name, item description, quantity, ordering practitioner, and signature.
42 CFR 410.38(d)Order date and practitioner signature
The SWO must be dated and signed by the treating practitioner. Undated or unsigned orders are treated as no order at all.
42 CFR 410.38(d)Practitioner NPI on the order
The ordering practitioner's NPI must appear on the order and match PECOS enrollment.
42 CFR 410.38(d)Face-to-face encounter documented
Chart notes must document an in-person (or permitted telehealth) encounter where the practitioner evaluated the patient for the item.
42 CFR 410.38(d)(2)Face-to-face within 6 months of the order
The qualifying encounter must have occurred within the 6 months before the order date.
42 CFR 410.38(d)(2)Medical necessity in the clinical record
The medical record — not just the order — must support why the item is medically necessary for this patient.
CMS PA Documentation ChecklistLength of need documented for rental items
Since the 2020 SWO rule, length of need is no longer a required element of the order itself — but the DME MAC PA portals ask for it, and the record must support the expected duration of use. AffirmDME requires an estimated length of need (1–99 months; 99 = lifetime) on every capped-rental item so the packet never stalls on it.
42 CFR 410.38(d) — SWO elements (2020 rule); DME MAC PA request fieldsWhat usually sinks these claims
- The chart says "patient desaturates" but the actual test report with SpO2/pO2 values was never collected
- Testing was done during a hospitalization or exacerbation — not a chronic stable state
- The qualifying test is too old relative to the order and initial claim
- Room-air versus supplemental-oxygen readings aren't distinguished in the record, leaving the qualifying value ambiguous
Stop checking this list by hand.
Upload your documentation and AffirmDME verifies every requirement above — with the citation — before you submit. Free to explore in sandbox mode, no credit card.
Check a case freeFAQ
What oxygen levels qualify for Medicare home oxygen?
Group I: arterial pO2 at or below 55 mmHg or SpO2 at or below 88%, at rest on room air (with sleep and exertion variants). Group II covers pO2 56–59 / SpO2 89 with specified secondary findings. The exact conditions are in LCD L33797 — what matters for documentation is that the actual test report and its values are in the file.
Does home oxygen require prior authorization?
No — E1390 isn't on the required prior-authorization list. It's enforced through medical review and ADRs after submission, and oxygen claims are audited heavily, so the record must be complete at billing time.
How does the 36-month rental rule work?
Medicare pays a monthly rental for 36 months; after that the supplier must continue providing the equipment with no further rental payments through month 60 (contents are still payable for gaseous/liquid systems), and the 5-year reasonable useful lifetime governs replacement. Budget your economics around that lifecycle from the first claim.
Get an email when the Required PA List changes.
CMS adds codes, the DME MACs revise LCDs, cycle deadlines arrive. We send a short note the week it happens, with what to do about it. No drip campaign. Unsubscribe in one click.
This guide summarizes Medicare requirements as implemented in AffirmDME's compliance engine, with citations to the governing sources. It is not legal or billing advice; LCDs and CMS policy change — always confirm against the current policy text linked above.
More guides
- Medicare ADR Letters: how to respond without losing the claim
- Medicare DME Documentation Requirements: the checklist every claim needs
- Medicare CPAP Documentation Requirements (E0601)
- Medicare BiPAP / RAD Documentation Requirements (E0470)
- Medicare Hospital Bed Documentation Requirements (E0260)
- Medicare Wheelchair & Power Mobility Prior Authorization (E1161)
- Medicare Knee Orthosis Documentation Requirements (L1833, L1832)
- Medicare TLSO Documentation Requirements (L0456, L0457, L0486)
- Medicare Air-Fluidized Bed Documentation Requirements (E0194)
- Medicare Ultralightweight Manual Wheelchair Requirements (K0005)
- Medicare Upper Limb Orthosis Requirements (L3761, L3916)
- Medicare Osteogenesis Stimulator Documentation Requirements (E0747, E0748)
- The Medicare DMEPOS Required Prior Authorization List, explained (2026)
- Probationary Prior Authorization for newly enrolled DMEPOS suppliers (Oct 15, 2026)
- The DMEPOS prior authorization exemption: how it works and how to keep it
- Which DME MAC handles your claim: Jurisdictions A, B, C, and D
- Standard Written Order (SWO) requirements for Medicare DME
- Medicare DME face-to-face encounter requirements
- Prior authorization vs ADR vs prepayment review vs TPE: what each means for a DME claim
- After a non-affirmed prior authorization: resubmit, deliver with an ABN, or wait
- Medicare DME proof of delivery requirements
- Preparing and submitting a DMEPOS prior authorization request
Unfamiliar term? The glossary defines ADR, SWO, UTN, PTAN and the rest; the PA List lookup checks any HCPCS code.